The iPhone's autocorrect feature is mostly handy, but it also tends to correct words you don't want it to. Reddit user wesontap shows off that one way to fix this is to add words in the shortcuts menu.

Add whatever words you like. Use the same word in both the phrase and shortcut box.

Now, when you type that bit of slang, the iPhone won't autocorrect it to something else. The shortcuts menu is great for all types of common phrases you might use, but this is especially handy if you like to use a bit of your own style of language.